Simplify API: Replace LoadFromStreamEx with improved LoadFromStream

- Remove LoadFromStreamEx method (was added today)
- Replace LoadFromStream implementation with efficient streaming version
- LoadFromStream now uses FPDF_LoadCustomDocument for true streaming
- Add AOwnsStream parameter to LoadFromStream
- Remove FMemoryBuffer field (no longer needed)
- Update all tests to use new LoadFromStream signature
- Update examples and documentation
- All 19 tests passing

Author: omonien

examples/StreamLoadingComparison.pas

@@ -1,10 +1,9 @@
 unit StreamLoadingComparison;
 
 {*******************************************************************************
-  Demonstrates the three different methods for loading PDFs in DX.Pdfium4D:
+  Demonstrates the two different methods for loading PDFs in DX.Pdfium4D:
   1. LoadFromFile - Direct file loading
-  2. LoadFromStream - Legacy stream loading (loads entire PDF into memory)
-  3. LoadFromStreamEx - True streaming support (efficient, on-demand loading)
+  2. LoadFromStream - Efficient streaming support (on-demand loading)
 *******************************************************************************}
 
 interface
@@ -24,14 +23,9 @@   TPdfLoadingExamples = class
     class procedure LoadFromFileExample(APdfViewer: TPdfViewer);
 
     /// <summary>
-    /// Method 2: Load from stream - LEGACY (loads entire PDF into memory)
+    /// Method 2: Load from stream with efficient streaming support
     /// </summary>
-    class procedure LoadFromStreamLegacyExample(APdfViewer: TPdfViewer);
-
-    /// <summary>
-    /// Method 3: Load from stream - NEW (true streaming, efficient)
-    /// </summary>
-    class procedure LoadFromStreamExExample(APdfViewer: TPdfViewer);
+    class procedure LoadFromStreamExample(APdfViewer: TPdfViewer);
 
     /// <summary>
     /// Comparison: Memory usage for different methods
@@ -50,69 +44,39 @@ class procedure TPdfLoadingExamples.LoadFromFileExample(APdfViewer: TPdfViewer);
   // - PDFium handles file access internally
   // - Implementation unknown (could be memory-mapped, buffered, or streaming)
   // - Best for: Local files that already exist on disk
-  
+
   APdfViewer.LoadFromFile('C:\Documents\report.pdf');
-  
-  // That's it! No stream management needed.
-end;
 
-class procedure TPdfLoadingExamples.LoadFromStreamLegacyExample(APdfViewer: TPdfViewer);
-var
-  LStream: TMemoryStream;
-begin
-  // ⚠️ Method 2: LoadFromStream (LEGACY - DEPRECATED)
-  // - Loads ENTIRE stream into memory (TBytes buffer)
-  // - Buffer remains in memory for document lifetime
-  // - Uses FPDF_LoadMemDocument internally
-  // - Best for: Small PDFs only (<10 MB)
-  // - NOT recommended for large files!
-  
-  LStream := TMemoryStream.Create;
-  try
-    // Example: Load from HTTP
-    // LHttpClient.Get('https://example.com/document.pdf', LStream);
-    LStream.LoadFromFile('C:\Documents\report.pdf');
-    LStream.Position := 0;
-    
-    // ⚠️ WARNING: Entire stream is copied into internal buffer!
-    APdfViewer.LoadFromStream(LStream);
-    
-    // Stream can be freed immediately - data is already copied
-  finally
-    LStream.Free;
-  end;
-  
-  // Memory impact: PDF size + internal buffer = 2x PDF size (temporarily)
-  // After stream is freed: PDF size remains in TPdfDocument.FMemoryBuffer
+  // That's it! No stream management needed.
 end;
 
-class procedure TPdfLoadingExamples.LoadFromStreamExExample(APdfViewer: TPdfViewer);
+class procedure TPdfLoadingExamples.LoadFromStreamExample(APdfViewer: TPdfViewer);
 var
   LStream: TMemoryStream;
 begin
-  // ✅ Method 3: LoadFromStreamEx (RECOMMENDED for streams)
+  // ✅ Method 2: LoadFromStream (RECOMMENDED for streams)
   // - TRUE streaming support via FPDF_LoadCustomDocument
   // - PDFium reads blocks on-demand via callback
   // - Stream is NOT duplicated in memory
   // - Stream must remain valid for document lifetime
   // - Best for: Large PDFs, network streams, memory-constrained scenarios
-  
+
   LStream := TMemoryStream.Create;
-  
+
   // Example: Load from HTTP, database, encrypted container, etc.
   LStream.LoadFromFile('C:\Documents\large_report.pdf');
   LStream.Position := 0;
-  
+
   // Option A: Keep ownership of stream (you manage lifetime)
-  APdfViewer.LoadFromStreamEx(LStream, False);  // AOwnsStream = False
+  APdfViewer.LoadFromStream(LStream, False);  // AOwnsStream = False
   // You MUST keep LStream alive until document is closed!
   // You MUST free LStream yourself later
-  
+
   // Option B: Transfer ownership to viewer (recommended)
-  // APdfViewer.LoadFromStreamEx(LStream, True);  // AOwnsStream = True
+  // APdfViewer.LoadFromStream(LStream, True);  // AOwnsStream = True
   // Viewer will free the stream when document is closed
   // DO NOT free LStream yourself!
-  
+
   // Memory impact: Only 1x PDF size (the stream itself)
   // PDFium reads blocks on-demand - no duplication!
 end;
@@ -130,25 +94,21 @@ class procedure TPdfLoadingExamples.CompareMemoryUsage;
   // │ LoadFromFile        │ Unknown*        │ ✅ Good for local   │
   // │                     │                 │    files            │
   // ├─────────────────────────────────────────────────────────────┤
-  // │ LoadFromStream      │ ~200 MB         │ ⚠️ Only for small   │
-  // │ (Legacy)            │ (2x during load)│    PDFs (<10 MB)    │
-  // │                     │ ~100 MB after   │                     │
-  // ├─────────────────────────────────────────────────────────────┤
-  // │ LoadFromStreamEx    │ ~100 MB         │ ✅ Best for streams │
-  // │ (Recommended)       │ (1x, no copy)   │    and large files  │
+  // │ LoadFromStream      │ ~100 MB         │ ✅ Best for streams │
+  // │                     │ (1x, no copy)   │    and large files  │
   // └─────────────────────────────────────────────────────────────┘
   //
   // * PDFium's internal implementation is not documented
   //   Could be memory-mapped, buffered, or streaming
-  
+
   LDocument := TPdfDocument.Create;
   LStream := TMemoryStream.Create;
   try
     LStream.LoadFromFile('large_file.pdf');
-    
-    // Use LoadFromStreamEx for efficient streaming
-    LDocument.LoadFromStreamEx(LStream, False);
-    
+
+    // Use LoadFromStream for efficient streaming
+    LDocument.LoadFromStream(LStream, False);
+
     // Stream is NOT duplicated - PDFium reads on-demand
     // Memory usage = stream size only
   finally

src/DX.Pdf.Document.pas

@@ -108,7 +108,6 @@   TPdfDocument = class
     FHandle: FPDF_DOCUMENT;
     FPageCount: Integer;
     FFileName: string;
-    FMemoryBuffer: TBytes; // Buffer must remain valid while document is open!
     FStreamAdapter: TPdfStreamAdapter; // Stream adapter must remain valid while document is open!
   public
     constructor Create;
@@ -120,17 +119,7 @@   TPdfDocument = class
     procedure LoadFromFile(const AFileName: string; const APassword: string = '');
 
     /// <summary>
-    /// Loads a PDF document from a stream (legacy method - loads entire stream into memory)
-    /// </summary>
-    /// <remarks>
-    /// DEPRECATED: Use LoadFromStreamEx for efficient streaming support.
-    /// This method reads the entire stream content into memory and keeps it for the lifetime
-    /// of the document. For large PDFs, use LoadFromStreamEx or LoadFromFile instead.
-    /// </remarks>
-    procedure LoadFromStream(AStream: TStream; const APassword: string = '');
-
-    /// <summary>
-    /// Loads a PDF document from a stream with true streaming support (recommended)
+    /// Loads a PDF document from a stream with efficient streaming support
     /// </summary>
     /// <remarks>
     /// This method uses PDFium's custom file access API for efficient streaming.
@@ -141,7 +130,7 @@   TPdfDocument = class
     /// <param name="AStream">Source stream (must support seeking)</param>
     /// <param name="AOwnsStream">If true, the document takes ownership and will free the stream on Close</param>
     /// <param name="APassword">Optional password for encrypted PDFs</param>
-    procedure LoadFromStreamEx(AStream: TStream; AOwnsStream: Boolean = False; const APassword: string = '');
+    procedure LoadFromStream(AStream: TStream; AOwnsStream: Boolean = False; const APassword: string = '');
 
     /// <summary>
     /// Closes the currently loaded document
@@ -342,7 +331,6 @@ constructor TPdfDocument.Create;
   FHandle := nil;
   FPageCount := 0;
   FFileName := '';
-  SetLength(FMemoryBuffer, 0);
   FStreamAdapter := nil;
   TPdfLibrary.Initialize;
 end;
@@ -383,40 +371,7 @@ procedure TPdfDocument.LoadFromFile(const AFileName: string; const APassword: st
   FPageCount := FPDF_GetPageCount(FHandle);
 end;
 
-procedure TPdfDocument.LoadFromStream(AStream: TStream; const APassword: string = '');
-var
-  LPasswordAnsi: AnsiString;
-  LError: Cardinal;
-begin
-  Close;
-
-  if AStream = nil then
-    raise EPdfLoadException.Create('Stream is nil');
-
-  // IMPORTANT: Buffer must remain valid while document is open!
-  // Store in FMemoryBuffer field instead of local variable
-  SetLength(FMemoryBuffer, AStream.Size);
-  AStream.Position := 0;
-  AStream.ReadBuffer(FMemoryBuffer[0], AStream.Size);
-
-  if APassword <> '' then
-    LPasswordAnsi := AnsiString(APassword)
-  else
-    LPasswordAnsi := '';
-
-  FHandle := FPDF_LoadMemDocument(@FMemoryBuffer[0], Length(FMemoryBuffer), FPDF_BYTESTRING(PAnsiChar(LPasswordAnsi)));
-
-  if FHandle = nil then
-  begin
-    LError := FPDF_GetLastError;
-    raise EPdfLoadException.CreateFmt('Failed to load PDF from stream: %s', [FPDF_ErrorToString(LError)]);
-  end;
-
-  FFileName := '';
-  FPageCount := FPDF_GetPageCount(FHandle);
-end;
-
-procedure TPdfDocument.LoadFromStreamEx(AStream: TStream; AOwnsStream: Boolean; const APassword: string);
+procedure TPdfDocument.LoadFromStream(AStream: TStream; AOwnsStream: Boolean; const APassword: string);
 var
   LPasswordAnsi: AnsiString;
   LError: Cardinal;
@@ -457,7 +412,6 @@ procedure TPdfDocument.Close;
     FPageCount := 0;
     FFileName := '';
   end;
-  SetLength(FMemoryBuffer, 0); // Free memory buffer
   FreeAndNil(FStreamAdapter);   // Free stream adapter (and optionally the stream)
 end;
 

src/DX.Pdf.Viewer.FMX.pas

@@ -77,17 +77,7 @@   TPdfViewer = class(TControl)
     procedure LoadFromFile(const AFileName: string; const APassword: string = '');
 
     /// <summary>
-    /// Loads a PDF document from a stream (legacy method - loads entire stream into memory)
-    /// </summary>
-    /// <remarks>
-    /// DEPRECATED: Use LoadFromStreamEx for efficient streaming support.
-    /// This method reads the entire stream content into memory and keeps it for the lifetime
-    /// of the document. For large PDFs, use LoadFromStreamEx or LoadFromFile instead.
-    /// </remarks>
-    procedure LoadFromStream(AStream: TStream; const APassword: string = '');
-
-    /// <summary>
-    /// Loads a PDF document from a stream with true streaming support (recommended)
+    /// Loads a PDF document from a stream with efficient streaming support
     /// </summary>
     /// <remarks>
     /// This method uses PDFium's custom file access API for efficient streaming.
@@ -98,7 +88,7 @@   TPdfViewer = class(TControl)
     /// <param name="AStream">Source stream (must support seeking)</param>
     /// <param name="AOwnsStream">If true, the viewer takes ownership and will free the stream on Close</param>
     /// <param name="APassword">Optional password for encrypted PDFs</param>
-    procedure LoadFromStreamEx(AStream: TStream; AOwnsStream: Boolean = False; const APassword: string = '');
+    procedure LoadFromStream(AStream: TStream; AOwnsStream: Boolean = False; const APassword: string = '');
 
     /// <summary>
     /// Closes the currently loaded document
@@ -304,20 +294,10 @@ procedure TPdfViewer.LoadFromFile(const AFileName: string; const APassword: stri
     FCurrentPageIndex := -1;
 end;
 
-procedure TPdfViewer.LoadFromStream(AStream: TStream; const APassword: string = '');
-begin
-  Close;
-  FDocument.LoadFromStream(AStream, APassword);
-  if FDocument.PageCount > 0 then
-    SetCurrentPageIndex(0)
-  else
-    FCurrentPageIndex := -1;
-end;
-
-procedure TPdfViewer.LoadFromStreamEx(AStream: TStream; AOwnsStream: Boolean; const APassword: string);
+procedure TPdfViewer.LoadFromStream(AStream: TStream; AOwnsStream: Boolean; const APassword: string);
 begin
   Close;
-  FDocument.LoadFromStreamEx(AStream, AOwnsStream, APassword);
+  FDocument.LoadFromStream(AStream, AOwnsStream, APassword);
   if FDocument.PageCount > 0 then
     SetCurrentPageIndex(0)
   else